U.S. patent application number 10/298690 was filed with the patent office on 2004-05-20 for printer chassis sidewall and platen assembly.
Invention is credited to Belbey, Jason, Bruhn, Victor, McNally, Stephen, Yraceburu, Robert M..
Application Number | 20040096257 10/298690 |
Document ID | / |
Family ID | 32176217 |
Filed Date | 2004-05-20 |
United States Patent
Application |
20040096257 |
Kind Code |
A1 |
McNally, Stephen ; et
al. |
May 20, 2004 |
Printer chassis sidewall and platen assembly
Abstract
The present invention provides a printer having a platen, a
chassis sidewall and an attachment portion connecting the platen to
the chassis sidewall. The attachment portion biases the platen
toward the chassis sidewall.
Inventors: |
McNally, Stephen;
(Vancouver, WA) ; Yraceburu, Robert M.; (Camas,
WA) ; Belbey, Jason; (Vancouver, WA) ; Bruhn,
Victor; (Vancouver, WA) |
Correspondence
Address: |
HEWLETT-PACKARD COMPANY
Intellectual Property Administration
P.O. Box 272400
Fort Collins
CO
80527-2400
US
|
Family ID: |
32176217 |
Appl. No.: |
10/298690 |
Filed: |
November 18, 2002 |
Current U.S.
Class: |
400/691 |
Current CPC
Class: |
B41J 11/08 20130101 |
Class at
Publication: |
400/691 |
International
Class: |
B41J 029/12 |
Claims
What is claimed is:
1. A printer, comprising: a platen; a chassis sidewall; an
attachment portion connected to the platen and chassis sidewall
such that the attachment portion is flexed to bias the platen
toward the chassis sidewall.
2. The printer according to claim 1, further comprising: a locking
datum tab extending from the chassis sidewall; and a receiving
formation in the platen; wherein the locking datum tab resides in
the receiving formation after the connection so as to prohibit
movement of the platen with respect to the chassis sidewall.
3. The printer according to claim 1, wherein the attachment portion
includes at least one flex portion that provides the elastic bias
to press the platen against the chassis sidewall.
4. The printer according to claim 3, further comprising: a base
portion attached to the chassis sidewall; and a mounting tab
connectable to the platen by a fastening member; wherein the flex
portion connects the base portion to the mounting tab.
5. The printer according to claim 4, wherein: the base portion
extends substantially perpendicularly from the chassis sidewall and
is integrally formed with the chassis sidewall; the mounting tab
has an aperture formed therein to receive the fastening member; and
the mounting tab is substantially parallel to the platen.
6. The printer according to claim 4, further comprising a stop tab
extending from the mounting tab, wherein the stop tab is positioned
proximate to the mounting tab at a position counterclockwise from
the chassis sidewall.
7. The printer according to claim 1, further comprising at least
one support datum tab formed on the chassis sidewall and positioned
against the platen to position the platen with respect to the
chassis sidewall, wherein the attachment portion biases the platen
against the support datum tab.
8. The printer according to claim 1, further comprising a mounting
plate positioned between the chassis sidewall and the mounting
plate, wherein the attachment forces the mounting plate between the
platen and the chassis sidewall.
9. The printer according to claim 1, further comprising: a leg
extending away from the chassis sidewall toward an inner area of
the printer; a flex portion connecting the leg with the chassis
sidewall; a mounting tab; a second flex portion connecting the
mounting tab to the leg; and a fastening member connecting the
mounting tab to the platen; wherein the flex portion and the second
flex portion bias the platen toward the chassis sidewall.
10. The printer according to claim 1, further comprising: a second
chassis sidewall positioned on an opposite end of the platen with
respect to the chassis sidewall; a second attachment portion
connecting the platen to the second chassis sidewall, the second
attachment portion being configured to bias the platen toward the
second chassis sidewall; and wherein a planar surface of the platen
is maintained in an unwarped condition.
11. The printer according to claim 1, wherein: the platen has an
aperture; the attachment portion has a mounting tab; the mounting
tab has an aperture; and an attachment member passes through the
aperture in the platen and the aperture in the mounting tab to bias
the platen to the chassis sidewall.
12. The printer according to claim 11, wherein the attachment
member is a threaded member rotatably secured to the outer
circumference of the aperture in the mounting tab.
13. The printer according to claim 11, wherein the aperture in the
mounting tab and the aperture in the platen are aligned with the
chassis sidewall.
14. A method for attaching a platen to a chassis sidewall, the
method comprising the steps of: providing a chassis sidewall having
a flexible attachment portion; providing a platen; and connecting
the attachment portion to the platen by an attachment member, the
connection flexing the attachment portion so as to bias the platen
toward the chassis sidewall.
15. The method according to claim 14, further comprising the steps
of: providing a stop tab on the attachment portion; and assembling
the attachment member to the attachment portion until the stop tab
substantially abuts the chassis sidewall.
16. The method according to claim 14, further comprising the steps
of: providing a mounting plate; positioning the mounting plate
between the platen and the chassis sidewall; connecting the
attachment portion to the chassis sidewall until the mounting plate
is retained between the platen and the chassis sidewall.
17. A printer comprising: a chassis sidewall; a platen; and an
attachment means for connecting the chassis sidewall to the platen
and biasing the platen toward the chassis sidewall.
18. A printer comprising: a chassis sidewall having at least one
location datum tab; a platen; and an attachment portion attached to
the chassis sidewall and the platen and drawing the platen toward
the datum tab on the chassis sidewall to prevent the platen from
moving away from the chassis sidewall.
19. The printer according to claim 18, wherein the printer further
comprises at least two location datum tabs positioned on opposite
sides of the attachment portion on the chassis sidewall to prevent
rotation of the platen with respect to the chassis sidewall about
at least one axis.
20. The printer according to claim 18, further comprising a locking
datum tab integrally formed with the chassis sidewall and
interlockingly engaged with a receiving portion on the platen to
prevent sliding movement between the platen and the chassis
sidewall.
Description
BACKGROUND OF THE INVENTION
[0001] In conventional image transfer devices, such as printers, a
platen is often provided to support print media, such as paper,
during printing. The platen provides a support surface for the
media in the region of the printer in which printing occurs.
Desirably, the platen maintains the media in a substantially flat
profile during printing. This helps alleviate print defects such as
paper jams and protect against potential damage to the printer. In
some situations, the platen can be warped due to moments exerted by
the mounting features of the platen and by associated fasteners.
This problem can be aggravated if the platen is formed of
lightweight, thin, stamped material.
SUMMARY OF THE INVENTION
[0002] An embodiment of the invention is directed to a printer
comprising a platen, a chassis sidewall, and an attachment portion
connecting the platen to the chassis sidewall. The attachment
portion biases the platen toward the chassis sidewall.
[0003] Other aspects and advantages of the present invention will
become apparent from the following detailed description taken in
conjunction with the accompanying drawings, illustrating by way of
example the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] The present invention will now be described, by way of
example, with reference to the accompanying drawings, in which:
[0005] FIG. 1 is a perspective view illustration of a platen
attached to chassis sidewalls according to a first embodiment of
the present invention;
[0006] FIG. 2 is a perspective view illustration of a platen
attached to a chassis sidewall according to the first embodiment of
the present invention;
[0007] FIG. 2a is a perspective view illustration of a chassis
sidewall before assembly according to the first embodiment of the
present invention;
[0008] FIG. 2b is a perspective view illustration of a chassis
sidewall after assembly according to the first embodiment of the
present invention;
[0009] FIG. 3 is a side view illustration of a platen attached to a
chassis sidewall according to the first embodiment of the present
invention;
[0010] FIG. 4 is a perspective view illustration of a platen
attached to a chassis sidewall according to a second embodiment of
the present invention;
[0011] FIG. 5 is a perspective view illustration of a chassis
sidewall according to the first embodiment of the present
invention;
[0012] FIG. 6 is a perspective view illustration of a chassis
sidewall according to a third embodiment of the present
invention;
[0013] FIG. 7 is a perspective view illustration of a platen
attached to a chassis sidewall according to the third embodiment of
the present invention;
[0014] FIG. 7a is a perspective view illustration of a chassis
sidewall before assembly according to the third embodiment of the
present invention;
[0015] FIG. 7b is a perspective view illustration of a chassis
sidewall before assembly according to the third embodiment of the
present invention;
[0016] FIG. 8 is a an exploded perspective view illustration of a
platen attached to a chassis sidewall according to the third
embodiment of the present invention;
[0017] FIG. 9 is a flow diagram illustration of an assembly method
of a platen to chassis sidewalls according to the embodiments of
the present invention; and
[0018] FIG. 10 is a front view illustration of a platen and chassis
sidewall according to a fourth embodiment of the present
invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0019] The present invention may be embodied in other specific
forms without departing from its spirit or essential
characteristics. The described embodiment is to be considered in
all respects only as illustrative and not restrictive. The scope of
the invention is, therefore, indicated by the appended claims
rather than by the foregoing description. All changes that come
within the meaning and range of equivalency of the claims are to be
embraced within their scope.
[0020] Referring now to FIGS. 1-3, a chassis platen assembly 14
according to one embodiment of the present invention is shown and
described. By way of the non limiting example depicted in FIG. 1,
the chassis platen assembly 14 includes a pair of opposed chassis
sidewalls 16 with platen 12 connected thereto. Recesses 35 are
formed in an upper portion of each of the chassis sidewalls 16, in
which platen 12 is positioned. Platen 12 is connected to the
chassis sidewalls 16 at respective attachment portions 36, as will
be described in greater detail hereinafter.
[0021] The illustrations depicted in FIGS. 2-8 illustrate
constructions of one of the chassis sidewalls 16. It is understood
that both chassis sidewalls 16 contain features similar to those
illustrated in each of the figures. However, it will be understood
by one skilled in the art that modifications and variations between
each of the sidewalls and combinations of any of the illustrated
preferred embodiments may be incorporated into chassis platen
assembly 14.
[0022] FIG. 2 illustrates an embodiment of the present invention in
which a locking datum tab 18 is integrally formed with the sidewall
16. The locking datum tab 18 generally extends from chassis
sidewall 16 and projects toward the platen 12 (in the assembly
orientation of platen 12 and chassis sidewall 16). In one
embodiment, locking datum tab 18 is received in receiving formation
18a in platen 12 to prevent movement of platen 12 along the Y-axis
direction relative to the chassis sidewalls 16. It is understood,
however, that other means and methods for restraining movement of
platen 12 along the Y-axis direction may be effectuated, and the
present invention is not limited to that disclosed herein. By way
of example of one such variation, platen 12 can include locking
datum tab 18 formed integrally therein while chassis sidewall 16
contains receiving formation 18a. One skilled in the art will
appreciate that other modifications and variations are possible
without deviating from the scope of the invention.
[0023] One or more support datum tabs are integrally formed in each
chassis sidewall 16. In a preferred embodiment, support datum tabs
19 and 21 extend from chassis sidewall 16 in a direction toward
platen 12 (in the assembly orientation of platen 12 and chassis
sidewall 16). Datum tabs 19 and 21 provide locating surfaces on
which to position and locate platen 12 along the Z-axis for proper
assembly to chassis sidewalls 16. Support datum tabs 19 and 21
position the platen with respect to the chassis sidewalls 16 and
other components generally included with the image transfer device
for which the present invention is applied.
[0024] In the embodiments depicted in FIGS. 2-3, attachment portion
36 is integrally formed with chassis sidewall 16. Attachment
portion 36 extends from chassis sidewall 16, through leg 33,
terminating at mounting tab 28. Chassis sidewall 16 preferably
includes one or more flex portions 27a and 27b. Leg 33 preferably
integrally connects to mounting tab 28 and chassis sidewall 16 via
flex portions 27a and 27b. Although the resulting shape depicted is
a Z shape, it will be understood by one skilled in the art that
other modifications and configurations are possible without
deviating from the scope of the invention. Leg 33 is separated from
chassis sidewall 16 by voids 23 and 25 to allow movement of leg 33
when chassis sidewall 16 is attached to platen 12 as will be
described in greater detail.
[0025] A fastening member 31, such as a screw, bolt or other
threaded means, has a shank 32 that extends through an opening in
platen 12 and engages an aperture 34 in mounting tab 28. Fastening
member 31 affixes platen 12 to the chassis sidewall 16. It should
be noted, however, that fastening member 31 is one representative
example of a fastening means used in conjunction with the present
invention, and that modifications and variations are ascertainable
by one skilled in the art. By way of a non-limiting example, the
fastening member 31 could also be a pop rivet, adhesive, welding or
other similar or known fastening means.
[0026] As best understood with respect to the non-limiting example
of FIG. 5, the centerline of aperture 34 is aligned with tabs 18,
19, 21 and chassis sidewall 16 with respect to the X-axis. As a
result, no moment is created about the Y-axis when fastening member
31 is connected to mounting tab 28. When platen 12 is connected to
the mounting tab 28, platen 12 rests on the datum tabs 19 and
21.
[0027] To minimize the moment about the X-axis, datum tabs 19 and
21, each located on an opposite side of the fastening member 31
along the Y-axis, provide support and resistance to rotation of
platen 12 about the X-axis. As such, when the fastening member 31
is tightened during attachment of platen 12 to mounting tab 28,
mounting tab 28 is pulled toward contact with the platen
undersurface 13. In this manner, the Z-axis location is not lost
because mounting tab 28 acts as a biasing spring/feature, not a
mounting feature, as will be described in greater detail.
[0028] With reference to FIG. 4, another embodiment of the
invention is shown having a modified attachment portion 36a.
Attachment portion 36a is similar in function to that shown and
described with reference to FIG. 2. However, attachment portion 36a
includes a shoulder 37 integrally connected to the sidewall 16. Leg
33 is interposed between and integrally connected to shoulder 37
and a mounting tab 28a. Shoulder 37 is typically wider than leg 33
to provide additional support for attachment portion 36a. The
thicker shoulder 37 provides increased support to resist plastic
deformation or shearing from torque generated from the rotation of
fastening member 31.
[0029] As shown in FIG. 4, additional support of platen 12 can be
provided by a transverse support 56 that is disposed between
chassis sidewall 16. The support as illustrated includes a pair of
laterally projecting ears 33a that help define a receiving
formation 33b. The shank 32 of the fastening member 31 passes
through the receiving formation 33b to engage an extruded hole 32a,
located at the underside of the mounting tab 28a. It will be
evident that there are additional embodiments and applications that
are not disclosed in the detailed description but which clearly
fall within the scope of the present invention.
[0030] With reference to FIGS. 1-5 and 9, a preferred embodiment of
the assembly and operation of the above described embodiments of
the present invention is shown and described by way of a
non-limiting example. In step 64 of FIG. 9, fastening members 31
such as screws are passed through apertures in platen 12 and
threaded to apertures 34 in mounting tabs 28. In step 66, fastening
members 31 are then secured to mounting tabs 28 until flex portions
of the attachment portions 36a are flexed and tabs 19 and 21 are
compressed against platen 12 for positioning of platen 12.
Attachment portion 36a is connected to platen 12 and chassis
sidewall 16 at distances to create a mechanical bias in the
attachment portion 36 and draw platen 12 and chassis sidewall 16
toward each other along the Z axis. Specifically, referring to
FIGS. 2a and 2b, "before" and "after" assembly configurations of
attachment portion 36 are shown. In FIG. 2a, attachment portion 36
is shown in its "un-sprung and unflexed" initial state. When
attachment portion 36 is attached to platen 12 as shown in FIG. 2b,
attachment portion 36 is stretched to its "sprung" position,
causing platen 12 to be drawn toward chassis sidewall 16. The
spacing of locations where attachment portion 36 connects to platen
12 and chassis sidewalls 16 stretch attachment portion 36 to
establish a "sprung" state or condition.
[0031] Flex portions 27a and 27b, as well as the remainder of
attachment portion 36, preferably allow mounting tabs 28 to move at
least in the Z and X directions. Accordingly, due to the
flexibility of attachment portion 36, torsional stresses induced by
fastening member 31, which are at least partially due to movement
of the mounting tabs 28a toward platen 12, are generally absorbed
by attachment portion 36 and not by platen 12. As such, as the
stress in platen 12 is lessened, stresses caused variations in
platen 12 are reduced, and platen 12 is better maintained in its
preferred substantially flat configuration. Flexing of mounting
tabs 28 also provides additional reduction of the bending load on
platen 12 when assembled to chassis sidewalls 16. To further reduce
movement in the X-direction, the attachment portion 36 can commonly
be made more flexible by utilizing a thinner leg 33. Making the
attachment portion 36 more flexible allows the attachment portion
36 to have controllable Z-axis hold-down forces. By way of a
non-limiting example, if one desires to increase the amount of
force exerted between platen 12 and chassis sidewall 16, the
flexibility of attachment portion 36 can be reduced, thereby
creating increased Z-axis hold-down forces when the platen is
attached to the attachment portion 36a.
[0032] Referring now to FIG. 6, an attachment portion 36b of
another embodiment is shown and described. By way of example,
without limitation, FIG. 6 illustrates attachment portion 36b as
including base portion 44, flex portion 46, and mounting tab 28b.
Preferably, base portion 44 is integrally formed with an edge of
aperture 50. However, it is understood that other alternate means
may be employed for attaching base portion 44 to chassis sidewall
16 such as by fastening means, adhesion, welding or other suitable
means.
[0033] By way of the example illustrated in FIG. 6, base portion 44
typically extends toward an interior area between opposing chassis
sidewall 16 (with reference to FIG. 1). However, base portion 44
and the remainder of the attachment portion can alternatively
extend outside the chassis sidewalls. Flex portion 46 integrally
extends from the upper portion (in the Z direction) of base portion
44 and traverses substantially parallel to a mating face of platen
12 (in an assembly configuration of platen 12 and chassis sidewall
16).A thickness in the X-axis direction of flex portion 46 is
reduced with respect to that of base portion 44 to provide
increased flexibility with respect to base portion 44 for reasons
which will be discussed in greater detail hereinafter. It should be
noted, however, that alternate modifications may be made to
attachment portion 36b to provide flexibility qualities beyond that
described herein. For instance, flex portion 46 may be constructed
of a different material from that of base portion 44, which
exhibits greater elastic deformation properties. Likewise, other
modifications to the dimensional characteristics of flex portion 46
may be made in conjunction to base portion 44 to provide elastic
deformation characteristics. Additionally, base portion 44 can be
modified to exhibit flexibility characteristics, thereby
eliminating flex portion 46 altogether. Moreover, it should be
noted that the flexibility characteristics exhibited by this
preferred embodiment may be elastic or plastic deformation.
[0034] With reference to FIG. 7, a preferred embodiment of mounting
tab 28b is described in greater detail. Mounting tab 28b has an
aperture 34 (e.g., see FIG. 8) passing therethrough along the
Z-direction. Preferably, mounting tab 28b is positioned
substantially parallel to platen 12 (in the assembly orientation of
platen 12 and chassis sidewall 16). In one embodiment, mounting tab
28b includes stop tab 54 that extends from mounting tab 28b. Stop
tab 54 is proximate inner side of chassis sidewall 16 to prevent
over-torqueing movement of mounting tab 28b with respect to chassis
sidewall 16. Of course, depending on the orientation of the
remainder of the attachment portion, stop tab 54 can also be
proximate the outer side of chassis sidewall 16. Stop tab 54 is
positioned on a counter clockwise position with respect to chassis
sidewall 16 and looking downward with respect to the figure, such
that rotation of fastening member 31 causes abutment of stop tab 54
with chassis sidewall 16 in the event of excessive torque, during
threading, of fastening member 31 as will be described in greater
detail.
[0035] Referring now to FIG. 8, one attachment of mounting tab 28b
to platen 12 is shown and described. A fastening member, such as a
fastening member 31 having a shank 32 extends through an opening 80
in the platen 12. As in the previous embodiments, other fastening
members beyond those described in the present figure may be used as
a fastening means for securing platen 12 to mounting tab 28b.
Preferably, the fastening member 31 is threaded to aperture 34 in
mounting tab 28b. In one embodiment, the diameter of threads on
shank 32 are sized slightly larger than the diameter of aperture
34. Accordingly, the threads of shank 32 machine corresponding
threads in the inner diameter of aperture 34 of mounting tab 28b to
create an inner locking engagement between shank 32 and mounting
tab 28b. As described with reference to FIG. 7, the extruded hole
32a secures to threads of shank 32 for providing additional
securing of mounting tab 28b to platen 12.
[0036] Mounting plate 56 is typically interposed between platen 12
and chassis sidewall 16.Mounting plate 56 includes locating tabs 58
and attachment tab 60. Each locating tab 58 has a bottom portion 82
that abuts locating surface 62 and a top portion 84 that abuts
platen 12. The machining of locating surfaces 62 and locating tabs
58 in conjunction with the thickness of locating tabs 58 positions
platen 12 at a desired level and orientation when platen 12 is
secured to mounting tab 28b (see FIG. 8). Accordingly, in a similar
manner as tabs 19 and 21 act to locate platen 12 in
previously-described embodiments, locating tabs 58 work in
conjunction with locating surfaces 62 of chassis sidewalls 16 to
position platen 12 in a proper configuration with respect to
components of the image transfer device for which the present
invention is applied.
[0037] With reference to FIGS. 6-9, an embodiment of the assembly
and operation of the above described embodiment of the present
invention is shown and described by way of a non-limiting example.
In step 64 of FIG. 9, fastening members such as fastening members
31 are passed through apertures in platen 12, mounting plate 56 and
threaded to apertures 34 in mounting tabs 28b. In step 66,
fastening members 31 are then secured to mounting tabs 28 until
flex portions of attachment portions 36b are flexed and locating
tabs 58 are compressed between locating surfaces 62 and platen 12
for positioning of platen 12. As can be seen from the figure,
attachment portion 36b is connected to platen 12 and chassis
sidewall 16 at distances to create a bias in the attachment portion
and draw platen 12 toward chassis sidewall 16 toward each other.
Flex portion 46 of each attachment portion 36b as well as the
remainder of attachment portion 36b allows mounting tab 28b to move
in the X, Y and Z directions. Additionally, attachment portion 36
allows mounting tab 28b to rotate at least about the Z axis.
Accordingly, due to the flexibility of attachment portion 36,
torsional stresses induced by fastening member 31 due to turning
and fastening are generally absorbed by attachment portion 36 and
not by the platen 12. As such, the reduced stresses in platen 12
act to reduce variations therein and to maintain platen 12 in its
preferred flat configuration. In some embodiments, to prevent
over-flexing or over-rotation of mounting tab 28b about the Z axis,
stop tab 54 (see FIG. 6) abuts chassis sidewall 16 at a
predetermined torque of mounting tab 28b about the Z axis. However,
stop tab 54 is not necessary for the operation of the present
invention and may be omitted. One skilled in the art will also
recognize that other types of stop features may be employed in the
present invention, or that no stop features at all may be employed,
and that the present invention is not limited to that disclosed in
the figures or discussed herein. As shown in FIG. 10, the generally
rectangular configuration of the present embodiment allows clearing
for the assembly of platen 12 to be positioned adjacent to
attachment portion 36b.
[0038] Referring to FIG. 10, another embodiment of the present
invention is shown and described. Here, mounting plate 56 is
replaced by tabs 70. Tabs 70 act as the locating surface for which
to position platen 12 with respect to chassis sidewalls 16.
Accordingly, with respect to the example assembly of the embodiment
illustrated in FIG. 9, in step 64 of FIG. 9, fastening members such
as fastening members 31 are passed through apertures in platen 12
and threaded to apertures 34 in mounting tabs 28b. In step 66,
fastening members 31 are then secured to mounting tabs 28 until
flex portions of the attachment portions 36b are flexed, tabs 70
are compressed against platen 12 for positioning of platen 12, and
a predetermined amount of torque has been applied to the fastening
member 31.
[0039] While the present invention has been particularly shown and
described with reference to the foregoing preferred and alternative
embodiments, it should be understood by those skilled in the art
that various alternatives to the embodiments of the invention
described herein may be employed in practicing the invention
without departing from the spirit and scope of the invention as
defined in the following claims. It is intended that the following
claims define the scope of the invention and that the method and
apparatus within the scope of these claims and their equivalents be
covered thereby. This description of the invention should be
understood to include all novel and non-obvious combinations of
elements described herein, and claims may be presented in this or a
later application to any novel and non-obvious combination of these
elements. The foregoing embodiments are illustrative, and no single
feature or element is essential to all possible combinations that
may be claimed in this or a later application. Where the claims
recite "a" or "a first" element of the equivalent thereof, such
claims should be understood to include incorporation of one or more
such elements, neither requiring nor excluding two or more such
elements.
* * * * *